Intestinal parasites, fleas, and ticks are a serious concern in Western Washington. These parasites do not require direct contact with other pets to be spread! The eggs of intestinal parasites live for many years in the soil in our temperate climate. The local dog parks and dog exercise areas are heavily contaminated with these eggs, and also with large numbers of fleas and small numbers of ticks.

For these reasons, we recommend monthly parasite prevention for all of our patients. These medicines are available as a pill, a topical medication, or a combination of both. The veterinary team can help make a parasite prevention plan specific for every patient.

The medicines which are given monthly to prevent intestinal parasites also prevent heartworm infection.

Heartworm is a parasite infecting dogs, cats and other mammals. It is spread by mosquitoes and has been prevalent in most of the United States for many years. Left untreated, heartworm infection can proceed to fatal heart failure. Until recently, residents of Washington state did not need to worry particularly about heartworm, but times are changing.

Changing climates, the fact so many people are traveling with their pets, and the redistribution of animals from the southern United States after disasters like Hurricane Katrina are all factors contributing to the introduction of heartworm into our area.

Because of these changes in the risk to our pets, we now recommend every dog give a small blood sample during his or her annual exam for a heartworm test. The test can be performed right here in the clinic.

For more detailed information about heartworm disease in dogs and cats, please visit the Heartworm Society website at

Although heartworm is uncommon in Washington, it will only remain that way if any infected animals are diagnosed and treated quickly, and animals at risk for infection are on heartworm preventive medications.

Any animal traveling outside Western Washington, and any animal with high exposure to other animals should take heartworm prevention medication. Heartworm is very easy to prevent by simply giving 1 chewable tablet to your dog once-a-month. Heartworm preventive medications are available right here at Mercer Island Veterinary Clinic, and require a doctor’s prescription. Heartworm preventive medications also prevent intestinal parasite infections like roundworm, hookworm and whipworm.